In vehicles of all kinds, it is often desirable to be able to detect when the vehicle is braking or otherwise decelerating. Braking can be detected in a variety of ways. One of the effects of braking is the reduction of vehicle speed. When a vehicle is moving at constant speed, the acceleration of the vehicle is zero. When the vehicle's speed is increasing, its acceleration is positive, and when the vehicle's speed is decreasing, its acceleration is negative (also known as deceleration). Brakes generally cause a reduction in speed by causing friction between a brake pad and a rotor or a drum. Specifically, braking creates friction to in order cause negative acceleration of the vehicle.
Measuring the acceleration of the vehicle is an effective way of sensing when the vehicle is braking. One possible method for measuring acceleration is by observing the speed of the vehicle, and how that speed changes over time. The speed of a vehicle can be measured in numerous ways. One method of measuring speed is to measure the distance the vehicle travels over a small amount of time. This distance may be obtained by using GPS device, or the like. Another method of measuring speed is to measure the wind speed. The wind speed may be measured using an anemometer or pitotube measurement tool. Unfortunately, these methods of measuring speed have proven inadequate for accurately detecting small speed changes in a timely fashion, and generally require expensive equipment. Alternatively, speed can be measured by simply reading the value from a speedometer. Typically, the speedometer value may be retrieved from an ODB II port of the vehicle. However, accessing the data from the ODB II port requires an extra device.
In the current market brake light systems are standard on vehicles of various types. These brake light systems are configured to turn on lights that signal individuals to the rear of the vehicle when the user applies the brake. These brake light systems typically include a brake switch, a wire harness and a signal lamp. The brake switch is closed by application of the brake pedal in order to complete a circuit that provides power from the vehicle battery to the signal lamp. The wire harness connects the switch to the signal lamp. The term “brake detection line” may also be used herein to refer to the electrical line in the vehicle connecting the brake switch or a power source to the signal lamp. The signal lamp may be any of various lights, such as an LED light, which provides a visual indication that the vehicle is braking. The advantage of this technology is the accuracy it achieves by directly detecting the physical braking action. Consequently, the visual indicator is turned on or off in perfect synchronization with application of the brakes. Aftermarket products exist that allow vehicle owners to add additional features associated with vehicle braking, such as flashing of the brake lights. However, these products are designed to tap directly into the vehicle's brake light system (e.g., lighting, wiring, electronics, etc.) such that installation of these products may be relatively difficult.